生物炭施用对紫色土旱坡地土壤氮流失形态及通量的影响

明确生物炭施用对紫色土旱坡地土壤氮流失形态及通量的影响,为提升紫色土旱坡地耕地质量及减少紫色土旱坡地农业面源污染发生风险提供科学依据.以油菜/玉米轮作农田生态系统为研究对象,通过田间试验,研究了不施肥(对照)、常规施肥、优化施肥及生物炭(化肥减量配施生物炭)这4个处理对紫色土旱坡地地表径流和壤中流氮素流失形态及通量的影响.结果表明:①在各施肥处理中,常规处理总径流量最大,为16 133 L·a~(-1),生物炭处理总径流量最小,为11 893 L·a~(-1).各施肥处理以壤中流为主要径流方式,壤中流流失量占总流失量的61.80%～68.60%;与对照(不施肥处理)相比,其余各施肥处理泥沙流失量均有所降低,其中常规处理降低的效果最明显.②铵态氮主要通过地表径流流失,占总流失通量的86.51%～96.58%;铵态氮流失通量最大的为施生物炭处理[0.69 kg·(hm~2·a)~(-1)].③各施肥处理产流中的颗粒态氮浓度均高于对照处理,且常规施肥处理的颗粒态氮流失通量最大,为2.87 kg·(hm~2·a)~(-1).④各施肥处理的壤中流和地表径流中的全氮浓度和硝态氮浓度均存在极显著正相关关系(P0.01).硝态氮是全氮流失的主要形态,且二者均以壤中流为主要流失途径;全氮通过壤中流流失占比为72.86%～89.13%,且常规施肥处理的全氮总流失通量最大,为35.58 kg·(hm~2·a)~(-1),而施生物炭处理全氮总流失通量最小,为21.49 kg·(hm~2·a)~(-1).化肥减量配施生物炭能明显降低径流量和氮的流失通量,可有效阻控农业面源污染发生的风险.     

区域大气环境模式RegAEMS中二次气溶胶的改进模拟研究

为了提升二次气溶胶的模拟精度,在区域大气环境模式RegAEMS中加入了硫酸盐气溶胶的两种新生成机制（NO₂+SO₂化学过程和过渡金属催化氧化（TMI））以及二次有机气溶胶（SOA）生成的挥发性有机物基集（VBS）方法.模拟了2020年1月上海市两次中度污染过程,并与观测数据进行对比验证.研究发现,两次污染过程硫氧转化率（SOR）均大于0.4,PM_2.5主要组分为SO₄^2-、NO₃^-、NH₄⁺等水溶性离子,占比为61.25%~63.85%.SOA占比为2.92%~3.0%.加入NO₂+SO₂化学过程和过渡金属催化氧化（TMI）后,硫酸盐模拟精度明显提升（相关系数（R）从0.49~0.63提升至0.58~0.67,相对标准偏差（NMB）从-35.0%~-36.5%提升至-17.3%~-14.2%）.两种化学过程在污染发展阶段平均贡献占比为23.3%~27.9%,这可能是造成污染条件下SO₄^2-浓度迅速增加的主要原因.VBS机制能够较好地模拟出SOA的变化趋势（相关系数为0.53~0.56）,由于硫酸盐和SOA生成机理的改进,RegAEMS在PM_2.5的模拟精度上有所提升（相对标准偏差（NMB）从-13.5%~-6.0%提升至-9.0%~-3.3%）.     

Comparing dark- and photo-Fenton-like degradation of emerging pollutant over photo-switchable Bi2WO6/CuFe2O4: Investigation on dominant reactive oxidation species

The extensive use of tetracycline hydrochloride (TCH) poses a threat to human health and the aquatic environment. Here, magnetic p-n Bi₂WO₆/CuFe₂O₄ catalyst was fabricated to efficiently remove TCH. The obtained Bi₂WO₆/CuFe₂O₄ exhibited 92.1% TCH degradation efficiency and 50.7% and 35.1% mineralization performance for TCH and raw secondary effluent from a wastewater treatment plant in a photo-Fenton-like system, respectively. The remarkable performance was attributed to the fact that photogenerated electrons accelerated the Fe(III)/Fe(II) and Cu(II)/Cu(I) conversion for the Fenton-like reaction between Fe(II)/Cu(I) and H₂O₂, thereby generating abundant ?OH for pollutant oxidation. Various environmental factors including H₂O₂ concentration, initial pH, catalyst dosage, TCH concentration and inorganic ions were explored. The reactive oxidation species (ROS) quenching results and electron spin resonance (ESR) spectra confirmed that ?O₂^? and ?OH were responsible for the dark and photo-Fenton-like systems, respectively. The degradation mechanisms and pathways of TCH were proposed, and the toxicity of products was evaluated. This work contributes a highly efficient and environmentally friendly catalyst and provides a clear mechanistic explanation for the removal of antibiotic pollutants in environmental remediation.     

Aging of PVDF and PES ultrafiltration membranes by sodium hypochlorite: Effect of solution pH

Sodium hypochlorite (NaClO) is a commonly applied cleaning agent for ultrafiltration membranes in water and wastewater treatment. Long-term exposure to NaClO might change the properties and performance of polymeric membranes, and ultimately shorten membrane lifespan. Active species in NaClO solution vary with solution pH, and the aging effects can change depending on the membrane material. In this study, the aging of polyvinylidene fluoride (PVDF) and polyethersulfone (PES) membranes by NaClO at pH 3–11 was investigated by examining variations in chemical composition, surface charge, surface morphology, mechanical strength, permeability, and retention ability. Polyvinyl pyrrolidone (PVP), which was blended in both membranes, was oxidized and dislodged due to NaClO aging at all investigated pH values, but the oxidation products and dislodgement ratio of PVP varied with solution pH. For the PVDF membrane, NaClO aging at pH 3–11 caused a moderate increase in permeability and decreased retention due to the oxidation and release of PVP. The tensile strength decreased only at pH 11 because of the defluorination of PVDF molecules. For the PES membrane, NaClO aging at all investigated pH resulted in chain scission of PES molecules, which was favored at pH 7 and 9, potentially due to the formation of free radicals. Therefore, a decrease in tensile strength and retention ability, as well as an increase in permeability, occurred in the PES membrane for NaClO aging at pH 3–11. Overall, the results can provide a basis for selecting chemical cleaning conditions for PVDF and PES membranes.     

Identification of close relationship between atmospheric oxidation and ozone formation regimes in a photochemically active region

Understanding ozone (O₃) formation regime is a prerequisite in formulating an effective O₃ pollution control strategy. Photochemical indicator is a simple and direct method in identifying O₃ formation regimes. Most used indicators are derived from observations, whereas the role of atmospheric oxidation is not in consideration, which is the core driver of O₃ formation. Thus, it may impact accuracy in signaling O₃ formation regimes. In this study, an advanced three-dimensional numerical modeling system was used to investigate the relationship between atmospheric oxidation and O₃ formation regimes during a long-lasting O₃ exceedance event in September 2017 over the Pearl River Delta (PRD) of China. We discovered a clear relationship between atmospheric oxidative capacity and O₃ formation regime. Over eastern PRD, O₃ formation was mainly in a NO_x-limited regime when HO₂/OH ratio was higher than 11, while in a VOC-limited regime when the ratio was lower than 9.5. Over central and western PRD, an HO₂/OH ratio higher than 5 and lower than 2 was indicative of NO_x-limited and VOC-limited regime, respectively. Physical contribution, including horizontal transport and vertical transport, may pose uncertainties on the indication of O₃ formation regime by HO₂/OH ratio. In comparison with other commonly used photochemical indicators, HO₂/OH ratio had the best performance in differentiating O₃ formation regimes. This study highlighted the necessities in using an atmospheric oxidative capacity-based indicator to infer O₃ formation regime, and underscored the importance of characterizing behaviors of radicals to gain insight in atmospheric processes leading to O₃ pollution over a photochemically active region.     

绿色技术专利强制许可法律问题研究

绿色技术专利强制许可要求将环境利益明确纳入公共利益范围,而专门的绿色技术专利强制许可制度则进一步要求针对绿色技术构建特殊许可通道。功能主义观念以环境保护目标的必要性来证成绿色技术专利强制许可的正当性,但没有解释绿色技术、环境保护、公共利益之间的具体联系,从而不能证明绿色技术专利强制许可背后的法律逻辑。法治主义视角下,从强制许可事由、审查程序以及许可费三方面来看,该制度会引起一系列的正当性问题。未来需要将专门的绿色技术专利强制许可制度限定在政府实施的范围内,并依据权利人自认来确定绿色技术的范围。     

钯/泡沫镍电极对水体中2-氯联苯的电催化脱氯作用

采用两室流通式隔膜电解池,研究了钯修饰泡沫镍电极对纯水相中2-氯联苯(2-CB)的电催化还原脱氯作用,考察了电流密度、pH 值和溶液流速对2-CB 脱氯率的影响.结果表明,当电流密度为1.5mA/cm²、阴极液pH 值为5.5、阴极液流速为7.4mL/(min·cm²)时,脱氯反应30min,2-CB 脱氯率达91.4%.脱氯产物包括联苯和苯基环己烷,根据脱氯过程碳平衡关系可确定该过程为逐步氢化反应.     

土壤中锁定残留芘在体外消化系统中的生物可给性（Oral Bioaccessibility of Bound Residue of Pyrene in Contamination Soils Determined by an in Vitro Gastrointestinal Model）

体外消化过程可能导致土壤中憎水有机污染物提取量增加.论文采用3种有机质含量不同的土壤进行体外消化实验,目的在于验证如下假设:土壤中部分锁定残留芘可以在人体消化系统中释放出来,若不考虑这部分贡献,常规提取方式获得的土壤污染浓度可能低估污染土壤口摄风险.研究结果证实:经体外消化的土壤的总芘提取量显著高于未经消化样品,其差别与土壤有机质含量有关.消化液中的胆汁盐是造成锁定残留芘释放的关键成份.在特定范围(2~20mg·mL-1)内,提取效率不受胆汁盐浓度影响.胆汁盐作用下锁定残留芘的释放为一次动力学过程.     

天津地区表层土中芳香烃污染物化学组成及分布特征

分析了天津地区不同环境功能区土壤中多环芳烃污染物的化学组成及其分布状况,并对其可能的污染源作初步分析.结果表明,天津地区不同环境功能区表层土壤样品中均分布有多种类型的烃类污染物,已经检测到的多环芳烃化合物主要包括萘、苊、苊烯、联苯、菲、惹烯、芴、二苯并呋喃(氧芴)、二苯并噻吩(硫芴)、萤蒽、芘、(艹屈)、苯并芴、苯并蒽、苯并萤蒽、苯并芘、(艹屈)、二苯并[a,h]蒽、茚并[1,2,3-cd]芘、苯并[g,h,i](艹屈)、三芳甾烷等系列数100种单体化合物,含量较高的主要有菲、甲基菲、萤蒽、芘、(艹屈)等.这些化合物的组成存在地域上的差异,同一地区不同土地使用情况、不同周围环境的样品中多环芳烃的组成特征也存在较大的差别,表明土壤中多环芳烃的污染源比较复杂,其中主要包括矿物油输入、化石燃料燃烧及木柴燃烧产物等,不同环境功能区各种污染源的贡献存在一定差别.      

胡敏酸对铜的鱼鳃生物有效性影响的计算机模拟

以彩虹方头鱼为模拟对象,用鱼鳃微环境测定装置和化学平衡计算方法(MINTEQA2),计算了含和不含胡敏酸的人工河水及暴露于其中的鱼鳃微环境中,不同pH条件下,铜的形态分布.研究了胡敏酸对鱼鳃内外的铜的形态分布及其生物有效性的影响,并讨论了pH对此的影响.计算结果表明,当胡敏酸存在时,胡敏酸络合态铜成为鱼鳃内外铜形态分布体系中的优势态,并引起铜生物有效性的降低.鱼鳃粘液和胡敏酸的共同作用使鱼鳃微环境中的生物有效铜含量低于外部水相.pH对铜形态分布及生物有效性的影响主要发生在碱性环境下.